Thank you for your reply. I had the same experience with the image being discarded (I should have mentioned that). The specific pictures were taken only to learn how to do a focus merge... so I'll take some different ones and try again. I tried to do it manually but it was too hard to do since the foreground pine tree branch was so detailed with pine needles etc.
As far as the "Affinity not Responding" it happens frequently in other edits including one image edits. Sometimes I'll be in the middle of an edit of one picture and it will happen. Sometimes it takes too long to recover if at all, like it's stuck, so I'll click to close the program; and it can take several minutes to close (a few times I've resorted to ctrl-alt-delete to close the program because it seems frozen) I clean my cache, history, etc frequently.
HP Pavilion dm4 Notebook PC, Intel core i5 CPU (M-450 @ 2.40 GHz) , 4GB Ram, 64 bit operating system, x64- based processor, Windows 10
Thanks, Terry